Interior Designer Broosk Saib lives in Putney, a peaceful, leafy suburb in southwest London, but his early childhood was spent under the shadow of war. He was born in Baghdad into an elegant Kurdish family; his father was a provincial governor. "There was constant political pressure," he remembers.

Respite came every summer, when the family would decamp to Putney. "I adored London," he says. "I loved riding my bicycle, shopping, the freedom and security, and the feeling of being respected as a human being." When Saib was 13, the threat of a coup back home became so intense that the family stayed in England for good. "The day we moved to London," he continues, "was the day I felt like I was born."

His Anglophile side soon emerged. The teenage Saib spent his spare time trawling the antiques markets of Portobello and Bermondsey and sifting through Christie's and Sotheby's auction catalogues. "My bedroom was the smallest room in the house," he explains, "but I filled it with rugs, pictures, and vases. Whenever we had guests, they all wanted to hang out in my room." After studying interior design, he began decorating the properties that his father was buying and renting out. "It was the late 1970s, and frog-green-carpeted bathrooms were in vogue," he says with amusement. "Instead, I would make fabulous bathrooms with marble imported from Italy."

Since then, Saib has honed a masculine yet cozy look that has attracted clients from around the world. The blueprint for that style, though, can be found in his own home. It's lodged in a somewhat institutional brown-brick tower built in 1936 by the Ministry of Defence to house war widows, but his apartment looks as far from the building's dowdy origins as can be imagined. In fact, Saib's interiors are the sort you might expect to find in a smart country house.

"When I bought this flat 12 years ago," he says, "it was like something out of a Jeeves and Wooster novel. Every room had a butler's pull, and there was a staff lavatory." Saib straightened some of the curved Art Deco walls to maximize square footage, but left intact a unique oval-shaped entrance hall. Two of the original four bedrooms were sacrificed to create a dining room and dressing room.

Saib initially gave the apartment a theatrical, Victorian look, with floral wallpapers, heavy ornamentation, and a four-poster bed. His recent redecoration aimed for something "quieter and less cluttered," he says. The walls are now coated with Farrow & Ball paints, in shades drawn from classic English country homes. His large collection of design books, once scattered, has been gathered up and neatly stacked in the massive bookcase that forms a dramatic frame over the head of his bed.

The designer describes the apartment's new look as "a tribute to the school of John Fowler," the renowned decorator who cofounded Colefax & Fowler in the 1930s. Old Masters hang on the walls, as do prints of European kings and queens and a framed embroidered waistcoat from the 18th century. The sofas and wing chairs, covered in velvet, are soft and inviting. There are vases he picked up while traveling in China and India. ("I'm quite a gypsy these days," he admits.) But while Saib clearly embraces traditional English style, he's not afraid to have fun with it. The dining room chairs are upholstered in Union Jacks; an oversize photo portrait of Queen Elizabeth captures the royal with her eyes shut.

Much of the furniture and lighting has been designed to move nomadically about the multifunctional space. When Saib indulges his hobby of photography, the drawing room morphs into a studio; when he's designing a new collection of jewelry, the apartment becomes a bustling workshop. By day the dining room is used as an office and a place where Saib can meet clients, but by evening all traces of work are stored away in the sideboard. "I work in a dining room and sleep in a library," he jokes.

But it's at night that the rooms truly come to life. Sometimes the entry hall's hanging light fixture is taken down and the peripatetic table is moved to make way for as many as 70 guests; the walls of the drawing room reflect the warm, clubby glow given off by lamps with red-silk shades. An exotic Vietnamese incense fills the rooms, while the aroma of roast lamb escapes from the kitchen. "I love to entertain at home," says Saib, "to cook and feed my friends. My doors are always open."